The only reason it might not work is if the morning glory vines cannot twine between the 1-inch spaces. Morning glories twine, so they have to be able to circle an upright stem or twig. Here is a video LINK showing a single revolution of a morning glory's climb.

That's my fear mindshift. I think I will return it to Home Depot. I was going to get the net trellis but it's white so I chose this. I'm planting them all along my back fence so I guess I'll just have to keep looking for something.

After seeing your reply I remembered a string trellis I saw once. Nails were driven into the bottom and top of a fence about 8-10 inches apart. Twine was tied to the first nail on the bottom row then run up to the first nail on the top row, looped around the nail, then run down to the second nail on the bottom. Continue looping the string around each nail head then running it to the next nail, and so on till you run out of nails, tying off to the last one. You only need vertical support strings, though you can add horizontal strings if you want. This trellis should last several years.

It's important that the fence belong to you. If it's your fence, the posts and rails should be visible in your yard, but some people put the picket boards on the inside. If you are not sure who owns the fence, you should probably see if your neighbor claims it, and get their permission first. Neighborhood feuds can get really nasty, so don't go there. I also recommend you use at least 16d (sixteen penny) nails so there is 3 inches of space between the twine and the fence. If you are nailing into rails the nails can go deeper, but if you are nailing into the pickets you only have about 1/2 inch before the nail goes through to the other side of the fence. Here is a LINK to a picture of this type of string trellis, but these people should have used longer nails to provide space for the vines to get behind the string.

That's perfect! Just today I bought what I need for this. We made a morning glory teepee. I think after reading your post I might put more vertical string on it. Should I remove the horizontal?

The boys seem to be pretty happy with the teepee :-)